Here's the title screen for I Love Lucy. I remember reading an article a bunch of years ago about producers who changed their title screen for just one episode, that it was it was a big decision because it was so expensive. Title and closing screens were basically like mini cartoons. All the backgrounds were hand drawn. If there were overlaid names they would have been put on cells then the two filmed. Then background music added. Now with computers it takes minutes to change one and can be done as often as they like. (here)
Here you can see the animation Joyce is talking about: